/**
 * @author qiao / https://github.com/qiao
 * @author mrdoob / http://mrdoob.com
 * @author alteredq / http://alteredqualia.com/
 * @author WestLangley / http://github.com/WestLangley
 * @author erich666 / http://erichaines.com
 */

// This set of controls performs orbiting, dollying (zooming), and panning.
// Unlike TrackballControls, it maintains the "up" direction object.up (+Y by default).
//
//    Orbit - left mouse / touch: one finger move
//    Zoom - middle mouse, or mousewheel / touch: two finger spread or squish
//    Pan - right mouse, or arrow keys / touch: three finger swipe

THREE.OrbitControls = function(object, domElement) {
    this.object = object;

    this.domElement = domElement !== undefined ? domElement : document;

    // Set to false to disable this control
    this.enabled = true;

    // "target" sets the location of focus, where the object orbits around
    this.target = new THREE.Vector3();

    // How far you can dolly in and out ( PerspectiveCamera only )
    this.minDistance = 0;
    this.maxDistance = Infinity;

    // How far you can zoom in and out ( OrthographicCamera only )
    this.minZoom = 0;
    this.maxZoom = Infinity;

    // How far you can orbit vertically, upper and lower limits.
    // Range is 0 to Math.PI radians.
    this.minPolarAngle = 0; // radians
    this.maxPolarAngle = Math.PI; // radians

    // How far you can orbit horizontally, upper and lower limits.
    // If set, must be a sub-interval of the interval [ - Math.PI, Math.PI ].
    this.minAzimuthAngle = -Infinity; // radians
    this.maxAzimuthAngle = Infinity; // radians

    // Set to true to enable damping (inertia)
    // If damping is enabled, you must call controls.update() in your animation loop
    this.enableDamping = false;
    this.dampingFactor = 0.25;

    // This option actually enables dollying in and out; left as "zoom" for backwards compatibility.
    // Set to false to disable zooming
    this.enableZoom = true;
    this.zoomSpeed = 1.0;

    // Set to false to disable rotating
    this.enableRotate = true;
    this.rotateSpeed = 1.0;

    // Set to false to disable panning
    this.enablePan = true;
    this.keyPanSpeed = 7.0; // pixels moved per arrow key push

    // Set to true to automatically rotate around the target
    // If auto-rotate is enabled, you must call controls.update() in your animation loop
    this.autoRotate = false;
    this.autoRotateSpeed = 2.0; // 30 seconds per round when fps is 60

    // Set to false to disable use of the keys
    this.enableKeys = true;

    // The four arrow keys
    this.keys = { LEFT: 37, UP: 38, RIGHT: 39, BOTTOM: 40 };

    // Mouse buttons
    this.mouseButtons = { ORBIT: THREE.MOUSE.LEFT, ZOOM: THREE.MOUSE.MIDDLE, PAN: THREE.MOUSE.RIGHT };

    // for reset
    this.target0 = this.target.clone();
    this.position0 = this.object.position.clone();
    this.zoom0 = this.object.zoom;

    //
    // public methods
    //

    /**
     * @desc 添加一个seek事件，在执行拖动，缩放的时候，触发此seek方法
     */
    this.seek = function() {};
    this.on = function(eventName, func) {
        if (eventName === 'seek') {
            this.seek = func;
        }
    };

    this.getPolarAngle = function() {
        return spherical.phi;
    };

    this.getAzimuthalAngle = function() {
        return spherical.theta;
    };

    this.saveState = function() {
        scope.target0.copy(scope.target);
        scope.position0.copy(scope.object.position);
        scope.zoom0 = scope.object.zoom;
    };

    this.reset = function() {
        scope.target.copy(scope.target0);
        scope.object.position.copy(scope.position0);
        scope.object.zoom = scope.zoom0;

        scope.object.updateProjectionMatrix();
        scope.dispatchEvent(changeEvent);

        scope.update();
        scope.seek();

        state = STATE.NONE;
    };

    // this method is exposed, but perhaps it would be better if we can make it private...
    this.update = (function() {
        var offset = new THREE.Vector3();

        // so camera.up is the orbit axis
        var quat = new THREE.Quaternion().setFromUnitVectors(object.up, new THREE.Vector3(0, 1, 0));
        var quatInverse = quat.clone().inverse();

        var lastPosition = new THREE.Vector3();
        var lastQuaternion = new THREE.Quaternion();

        return function update() {
            var position = scope.object.position;

            offset.copy(position).sub(scope.target);

            // rotate offset to "y-axis-is-up" space
            offset.applyQuaternion(quat);

            // angle from z-axis around y-axis
            spherical.setFromVector3(offset);

            if (scope.autoRotate && state === STATE.NONE) {
                rotateLeft(getAutoRotationAngle());
            }

            spherical.theta += sphericalDelta.theta;
            spherical.phi += sphericalDelta.phi;

            // restrict theta to be between desired limits
            spherical.theta = Math.max(scope.minAzimuthAngle, Math.min(scope.maxAzimuthAngle, spherical.theta));

            // restrict phi to be between desired limits
            spherical.phi = Math.max(scope.minPolarAngle, Math.min(scope.maxPolarAngle, spherical.phi));

            spherical.makeSafe();

            spherical.radius *= scale;

            // restrict radius to be between desired limits
            spherical.radius = Math.max(scope.minDistance, Math.min(scope.maxDistance, spherical.radius));

            // move target to panned location
            scope.target.add(panOffset);

            offset.setFromSpherical(spherical);

            // rotate offset back to "camera-up-vector-is-up" space
            offset.applyQuaternion(quatInverse);

            position.copy(scope.target).add(offset);

            scope.object.lookAt(scope.target);

            if (scope.enableDamping === true) {
                sphericalDelta.theta *= 1 - scope.dampingFactor;
                sphericalDelta.phi *= 1 - scope.dampingFactor;
            } else {
                sphericalDelta.set(0, 0, 0);
            }

            scale = 1;
            panOffset.set(0, 0, 0);

            // update condition is:
            // min(camera displacement, camera rotation in radians)^2 > EPS
            // using small-angle approximation cos(x/2) = 1 - x^2 / 8

            if (
                zoomChanged ||
                lastPosition.distanceToSquared(scope.object.position) > EPS ||
                8 * (1 - lastQuaternion.dot(scope.object.quaternion)) > EPS
            ) {
                scope.dispatchEvent(changeEvent);

                lastPosition.copy(scope.object.position);
                lastQuaternion.copy(scope.object.quaternion);
                zoomChanged = false;

                return true;
            }

            return false;
        };
    })();

    this.dispose = function() {
        scope.domElement.removeEventListener('contextmenu', onContextMenu, false);
        scope.domElement.removeEventListener('mousedown', onMouseDown, false);
        scope.domElement.removeEventListener('wheel', onMouseWheel, false);

        scope.domElement.removeEventListener('touchstart', onTouchStart, false);
        scope.domElement.removeEventListener('touchend', onTouchEnd, false);
        scope.domElement.removeEventListener('touchmove', onTouchMove, false);

        document.removeEventListener('mousemove', onMouseMove, false);
        document.removeEventListener('mouseup', onMouseUp, false);

        window.removeEventListener('keydown', onKeyDown, false);

        //scope.dispatchEvent( { type: 'dispose' } ); // should this be added here?
    };

    //
    // internals
    //

    var scope = this;

    var changeEvent = { type: 'change' };
    var startEvent = { type: 'start' };
    var endEvent = { type: 'end' };

    var STATE = { NONE: -1, ROTATE: 0, DOLLY: 1, PAN: 2, TOUCH_ROTATE: 3, TOUCH_DOLLY: 4, TOUCH_PAN: 5 };

    var state = STATE.NONE;

    var EPS = 0.000001;

    // current position in spherical coordinates
    var spherical = new THREE.Spherical();
    var sphericalDelta = new THREE.Spherical();

    var scale = 1;
    var panOffset = new THREE.Vector3();
    var zoomChanged = false;

    var rotateStart = new THREE.Vector2();
    var rotateEnd = new THREE.Vector2();
    var rotateDelta = new THREE.Vector2();

    var panStart = new THREE.Vector2();
    var panEnd = new THREE.Vector2();
    var panDelta = new THREE.Vector2();

    var dollyStart = new THREE.Vector2();
    var dollyEnd = new THREE.Vector2();
    var dollyDelta = new THREE.Vector2();

    function getAutoRotationAngle() {
        return ((2 * Math.PI) / 60 / 60) * scope.autoRotateSpeed;
    }

    function getZoomScale() {
        return Math.pow(0.95, scope.zoomSpeed);
    }

    function rotateLeft(angle) {
        sphericalDelta.theta -= angle;
    }

    function rotateUp(angle) {
        sphericalDelta.phi -= angle;
    }

    var panLeft = (function() {
        var v = new THREE.Vector3();

        return function panLeft(distance, objectMatrix) {
            v.setFromMatrixColumn(objectMatrix, 0); // get X column of objectMatrix
            v.multiplyScalar(-distance);

            panOffset.add(v);
        };
    })();

    var panUp = (function() {
        var v = new THREE.Vector3();

        return function panUp(distance, objectMatrix) {
            v.setFromMatrixColumn(objectMatrix, 1); // get Y column of objectMatrix
            v.multiplyScalar(distance);

            panOffset.add(v);
        };
    })();

    // deltaX and deltaY are in pixels; right and down are positive
    var pan = (function() {
        var offset = new THREE.Vector3();

        return function pan(deltaX, deltaY) {
            var element = scope.domElement === document ? scope.domElement.body : scope.domElement;

            if (scope.object instanceof THREE.PerspectiveCamera) {
                // perspective
                var position = scope.object.position;
                offset.copy(position).sub(scope.target);
                var targetDistance = offset.length();

                // half of the fov is center to top of screen
                targetDistance *= Math.tan(((scope.object.fov / 2) * Math.PI) / 180.0);

                // we actually don't use screenWidth, since perspective camera is fixed to screen height
                panLeft((2 * deltaX * targetDistance) / element.clientHeight, scope.object.matrix);
                panUp((2 * deltaY * targetDistance) / element.clientHeight, scope.object.matrix);
            } else if (scope.object instanceof THREE.OrthographicCamera) {
                // orthographic
                panLeft(
                    (deltaX * (scope.object.right - scope.object.left)) / scope.object.zoom / element.clientWidth,
                    scope.object.matrix
                );
                panUp(
                    (deltaY * (scope.object.top - scope.object.bottom)) / scope.object.zoom / element.clientHeight,
                    scope.object.matrix
                );
            } else {
                // camera neither orthographic nor perspective
                console.warn('WARNING: OrbitControls.js encountered an unknown camera type - pan disabled.');
                scope.enablePan = false;
            }
        };
    })();

    function dollyIn(dollyScale) {
        if (scope.object instanceof THREE.PerspectiveCamera) {
            scale /= dollyScale;
        } else if (scope.object instanceof THREE.OrthographicCamera) {
            scope.object.zoom = Math.max(scope.minZoom, Math.min(scope.maxZoom, scope.object.zoom * dollyScale));
            scope.object.updateProjectionMatrix();
            zoomChanged = true;
        } else {
            console.warn('WARNING: OrbitControls.js encountered an unknown camera type - dolly/zoom disabled.');
            scope.enableZoom = false;
        }
    }

    function dollyOut(dollyScale) {
        if (scope.object instanceof THREE.PerspectiveCamera) {
            scale *= dollyScale;
        } else if (scope.object instanceof THREE.OrthographicCamera) {
            scope.object.zoom = Math.max(scope.minZoom, Math.min(scope.maxZoom, scope.object.zoom / dollyScale));
            scope.object.updateProjectionMatrix();
            zoomChanged = true;
        } else {
            console.warn('WARNING: OrbitControls.js encountered an unknown camera type - dolly/zoom disabled.');
            scope.enableZoom = false;
        }
    }

    //
    // event callbacks - update the object state
    //

    function handleMouseDownRotate(event) {
        //console.log( 'handleMouseDownRotate' );

        rotateStart.set(event.clientX, event.clientY);
    }

    function handleMouseDownDolly(event) {
        //console.log( 'handleMouseDownDolly' );

        dollyStart.set(event.clientX, event.clientY);
    }

    function handleMouseDownPan(event) {
        //console.log( 'handleMouseDownPan' );

        panStart.set(event.clientX, event.clientY);
    }

    function handleMouseMoveRotate(event) {
        //console.log( 'handleMouseMoveRotate' );

        rotateEnd.set(event.clientX, event.clientY);
        rotateDelta.subVectors(rotateEnd, rotateStart);

        var element = scope.domElement === document ? scope.domElement.body : scope.domElement;

        // rotating across whole screen goes 360 degrees around
        rotateLeft(((2 * Math.PI * rotateDelta.x) / element.clientWidth) * scope.rotateSpeed);

        // rotating up and down along whole screen attempts to go 360, but limited to 180
        rotateUp(((2 * Math.PI * rotateDelta.y) / element.clientHeight) * scope.rotateSpeed);

        rotateStart.copy(rotateEnd);

        scope.update();
        scope.seek();
    }

    function handleMouseMoveDolly(event) {
        //console.log( 'handleMouseMoveDolly' );

        dollyEnd.set(event.clientX, event.clientY);

        dollyDelta.subVectors(dollyEnd, dollyStart);

        if (dollyDelta.y > 0) {
            dollyIn(getZoomScale());
        } else if (dollyDelta.y < 0) {
            dollyOut(getZoomScale());
        }

        dollyStart.copy(dollyEnd);

        scope.update();
        scope.seek();
    }

    function handleMouseMovePan(event) {
        //console.log( 'handleMouseMovePan' );

        panEnd.set(event.clientX, event.clientY);

        panDelta.subVectors(panEnd, panStart);

        pan(panDelta.x, panDelta.y);

        panStart.copy(panEnd);

        scope.update();
        scope.seek();
    }

    function handleMouseUp(event) {
        // console.log( 'handleMouseUp' );
    }

    function handleMouseWheel(event) {
        // console.log( 'handleMouseWheel' );

        if (event.deltaY < 0) {
            dollyOut(getZoomScale());
        } else if (event.deltaY > 0) {
            dollyIn(getZoomScale());
        }

        scope.update();
        scope.seek();
    }

    function handleKeyDown(event) {
        //console.log( 'handleKeyDown' );

        switch (event.keyCode) {
            case scope.keys.UP:
                pan(0, scope.keyPanSpeed);
                scope.update();
                scope.seek();
                break;

            case scope.keys.BOTTOM:
                pan(0, -scope.keyPanSpeed);
                scope.update();
                scope.seek();
                break;

            case scope.keys.LEFT:
                pan(scope.keyPanSpeed, 0);
                scope.update();
                scope.seek();
                break;

            case scope.keys.RIGHT:
                pan(-scope.keyPanSpeed, 0);
                scope.update();
                scope.seek();
                break;
        }
    }

    function handleTouchStartRotate(event) {
        //console.log( 'handleTouchStartRotate' );

        rotateStart.set(event.touches[0].pageX, event.touches[0].pageY);
    }

    function handleTouchStartDolly(event) {
        //console.log( 'handleTouchStartDolly' );

        var dx = event.touches[0].pageX - event.touches[1].pageX;
        var dy = event.touches[0].pageY - event.touches[1].pageY;

        var distance = Math.sqrt(dx * dx + dy * dy);

        dollyStart.set(0, distance);
    }

    function handleTouchStartPan(event) {
        //console.log( 'handleTouchStartPan' );

        panStart.set(event.touches[0].pageX, event.touches[0].pageY);
    }

    function handleTouchMoveRotate(event) {
        //console.log( 'handleTouchMoveRotate' );

        rotateEnd.set(event.touches[0].pageX, event.touches[0].pageY);
        rotateDelta.subVectors(rotateEnd, rotateStart);

        var element = scope.domElement === document ? scope.domElement.body : scope.domElement;

        // rotating across whole screen goes 360 degrees around
        rotateLeft(((2 * Math.PI * rotateDelta.x) / element.clientWidth) * scope.rotateSpeed);

        // rotating up and down along whole screen attempts to go 360, but limited to 180
        rotateUp(((2 * Math.PI * rotateDelta.y) / element.clientHeight) * scope.rotateSpeed);

        rotateStart.copy(rotateEnd);

        scope.update();
        scope.seek();
    }

    function handleTouchMoveDolly(event) {
        //console.log( 'handleTouchMoveDolly' );

        var dx = event.touches[0].pageX - event.touches[1].pageX;
        var dy = event.touches[0].pageY - event.touches[1].pageY;

        var distance = Math.sqrt(dx * dx + dy * dy);

        dollyEnd.set(0, distance);

        dollyDelta.subVectors(dollyEnd, dollyStart);

        if (dollyDelta.y > 0) {
            dollyOut(getZoomScale());
        } else if (dollyDelta.y < 0) {
            dollyIn(getZoomScale());
        }

        dollyStart.copy(dollyEnd);

        scope.update();
        scope.seek();
    }

    function handleTouchMovePan(event) {
        //console.log( 'handleTouchMovePan' );

        panEnd.set(event.touches[0].pageX, event.touches[0].pageY);

        panDelta.subVectors(panEnd, panStart);

        pan(panDelta.x, panDelta.y);

        panStart.copy(panEnd);

        scope.update();
        scope.seek();
    }

    function handleTouchEnd(event) {
        //console.log( 'handleTouchEnd' );
    }

    //
    // event handlers - FSM: listen for events and reset state
    //

    function onMouseDown(event) {
        if (scope.enabled === false) return;

        event.preventDefault();

        switch (event.button) {
            case scope.mouseButtons.ORBIT:
                if (scope.enableRotate === false) return;

                handleMouseDownRotate(event);

                state = STATE.ROTATE;

                break;

            case scope.mouseButtons.ZOOM:
                if (scope.enableZoom === false) return;

                handleMouseDownDolly(event);

                state = STATE.DOLLY;

                break;

            case scope.mouseButtons.PAN:
                if (scope.enablePan === false) return;

                handleMouseDownPan(event);

                state = STATE.PAN;

                break;
        }

        if (state !== STATE.NONE) {
            document.addEventListener('mousemove', onMouseMove, false);
            document.addEventListener('mouseup', onMouseUp, false);

            scope.dispatchEvent(startEvent);
        }
    }

    function onMouseMove(event) {
        if (scope.enabled === false) return;

        event.preventDefault();

        switch (state) {
            case STATE.ROTATE:
                if (scope.enableRotate === false) return;

                handleMouseMoveRotate(event);

                break;

            case STATE.DOLLY:
                if (scope.enableZoom === false) return;

                handleMouseMoveDolly(event);

                break;

            case STATE.PAN:
                if (scope.enablePan === false) return;

                handleMouseMovePan(event);

                break;
        }
    }

    function onMouseUp(event) {
        if (scope.enabled === false) return;

        handleMouseUp(event);

        document.removeEventListener('mousemove', onMouseMove, false);
        document.removeEventListener('mouseup', onMouseUp, false);

        scope.dispatchEvent(endEvent);

        state = STATE.NONE;
    }

    function onMouseWheel(event) {
        if (scope.enabled === false || scope.enableZoom === false || (state !== STATE.NONE && state !== STATE.ROTATE))
            return;

        event.preventDefault();
        event.stopPropagation();

        handleMouseWheel(event);

        scope.dispatchEvent(startEvent); // not sure why these are here...
        scope.dispatchEvent(endEvent);
    }

    function onKeyDown(event) {
        if (scope.enabled === false || scope.enableKeys === false || scope.enablePan === false) return;

        handleKeyDown(event);
    }

    function onTouchStart(event) {
        if (scope.enabled === false) return;

        switch (event.touches.length) {
            case 1: // one-fingered touch: rotate
                if (scope.enableRotate === false) return;

                handleTouchStartRotate(event);

                state = STATE.TOUCH_ROTATE;

                break;

            case 2: // two-fingered touch: dolly
                if (scope.enableZoom === false) return;

                handleTouchStartDolly(event);

                state = STATE.TOUCH_DOLLY;

                break;

            case 3: // three-fingered touch: pan
                if (scope.enablePan === false) return;

                handleTouchStartPan(event);

                state = STATE.TOUCH_PAN;

                break;

            default:
                state = STATE.NONE;
        }

        if (state !== STATE.NONE) {
            scope.dispatchEvent(startEvent);
        }
    }

    function onTouchMove(event) {
        if (scope.enabled === false) return;

        event.preventDefault();
        event.stopPropagation();

        switch (event.touches.length) {
            case 1: // one-fingered touch: rotate
                if (scope.enableRotate === false) return;
                if (state !== STATE.TOUCH_ROTATE) return; // is this needed?...

                handleTouchMoveRotate(event);

                break;

            case 2: // two-fingered touch: dolly
                if (scope.enableZoom === false) return;
                if (state !== STATE.TOUCH_DOLLY) return; // is this needed?...

                handleTouchMoveDolly(event);

                break;

            case 3: // three-fingered touch: pan
                if (scope.enablePan === false) return;
                if (state !== STATE.TOUCH_PAN) return; // is this needed?...

                handleTouchMovePan(event);

                break;

            default:
                state = STATE.NONE;
        }
    }

    function onTouchEnd(event) {
        if (scope.enabled === false) return;

        handleTouchEnd(event);

        scope.dispatchEvent(endEvent);

        state = STATE.NONE;
    }

    function onContextMenu(event) {
        if (scope.enabled === false) return;

        event.preventDefault();
    }

    //

    scope.domElement.addEventListener('contextmenu', onContextMenu, false);

    scope.domElement.addEventListener('mousedown', onMouseDown, false);
    scope.domElement.addEventListener('wheel', onMouseWheel, false);

    scope.domElement.addEventListener('touchstart', onTouchStart, false);
    scope.domElement.addEventListener('touchend', onTouchEnd, false);
    scope.domElement.addEventListener('touchmove', onTouchMove, false);

    window.addEventListener('keydown', onKeyDown, false);

    // force an update at start

    this.update();
    this.seek();
};

THREE.OrbitControls.prototype = Object.create(THREE.EventDispatcher.prototype);
THREE.OrbitControls.prototype.constructor = THREE.OrbitControls;

Object.defineProperties(THREE.OrbitControls.prototype, {
    center: {
        get: function() {
            console.warn('THREE.OrbitControls: .center has been renamed to .target');
            return this.target;
        }
    },

    // backward compatibility

    noZoom: {
        get: function() {
            console.warn('THREE.OrbitControls: .noZoom has been deprecated. Use .enableZoom instead.');
            return !this.enableZoom;
        },

        set: function(value) {
            console.warn('THREE.OrbitControls: .noZoom has been deprecated. Use .enableZoom instead.');
            this.enableZoom = !value;
        }
    },

    noRotate: {
        get: function() {
            console.warn('THREE.OrbitControls: .noRotate has been deprecated. Use .enableRotate instead.');
            return !this.enableRotate;
        },

        set: function(value) {
            console.warn('THREE.OrbitControls: .noRotate has been deprecated. Use .enableRotate instead.');
            this.enableRotate = !value;
        }
    },

    noPan: {
        get: function() {
            console.warn('THREE.OrbitControls: .noPan has been deprecated. Use .enablePan instead.');
            return !this.enablePan;
        },

        set: function(value) {
            console.warn('THREE.OrbitControls: .noPan has been deprecated. Use .enablePan instead.');
            this.enablePan = !value;
        }
    },

    noKeys: {
        get: function() {
            console.warn('THREE.OrbitControls: .noKeys has been deprecated. Use .enableKeys instead.');
            return !this.enableKeys;
        },

        set: function(value) {
            console.warn('THREE.OrbitControls: .noKeys has been deprecated. Use .enableKeys instead.');
            this.enableKeys = !value;
        }
    },

    staticMoving: {
        get: function() {
            console.warn('THREE.OrbitControls: .staticMoving has been deprecated. Use .enableDamping instead.');
            return !this.enableDamping;
        },

        set: function(value) {
            console.warn('THREE.OrbitControls: .staticMoving has been deprecated. Use .enableDamping instead.');
            this.enableDamping = !value;
        }
    },

    dynamicDampingFactor: {
        get: function() {
            console.warn('THREE.OrbitControls: .dynamicDampingFactor has been renamed. Use .dampingFactor instead.');
            return this.dampingFactor;
        },

        set: function(value) {
            console.warn('THREE.OrbitControls: .dynamicDampingFactor has been renamed. Use .dampingFactor instead.');
            this.dampingFactor = value;
        }
    }
});
